66pony is right. I do not have my papers but I think the 280 is a bit over 6 tons gross. not the same as dry weight.
and yes the loan stuff is why the feds get the registrations, because banks are all interstate now and they like the registration and lien registrations at the fed level. I bought a boat that was already CG documented, and renewed it....but I might not do it again. De-registration is an option with the feds if the boat is rec only. In our coasatal area we have lots of federal and state waters running together and the fed registration is the way to be sure you are covered everywhere. but until we figure out how to increase the 280 fuel tank size the real reason for the doc is to get picked up by the Coast Guard after you go too far off shore and cannot get back!
Your 280 displaces 9 tons.